How we cite our quotes: (Chapter.Paragraph)
Quote #4
Garp's conviction that Franz Grillparzer was a "bad" writer seemed to provide the young man with his first real confidence as an artist—even before he had written anything. (5.51)
The young eat the old—this is especially true when it comes to the arts. You don't have to look very far back in history of literature to find examples of this in real life.
Quote #5
What Garp was savoring was the beginning of a writer's long-sought trance, wherein the world falls under one embracing ton of voice. (6.48)
Garp's early career is hindered by his difficulty finding his "voice." A writer's "voice" is hard to define, but is an integral part of any meaningful body of work.
Quote #6
His first novel [...] suffered from the pretentious weight of all that fascist history he had taken no real part in. His second novel suffered his failure at imagining enough. (8.218)
As Garp becomes an established author, he starts struggling to walk the line between what he understands as "imagined" fiction and "autobiographical" fiction. As we come to learn, this is a difficult balance to achieve.